There is considerable interest in the food industry in combining milk and fruit juice to form stable, healthful beverage products that have a desirable taste and mouthfeel. Milk is well known as a healthful source of protein and calcium and fruit and fruit juice generally provide a wonderful combination of vitamins and other healthy nutrients, which well educated consumers prefer over other less healthful products. The difficulty in providing a healthful product containing milk and fruit or fruit juice has generally been the lack of stability in such products. There are several stability problems to overcome. Microbial stability is the first problem people generally consider in regard to food products. In the case of the present products, microbial stability, which can be a significant problem in products having a higher pH, is generally a lesser concern, because the preferred products generally have a relatively low pH. Stability with respect to the coagulation of milk and other proteins, however, is a significant concern in products having a lower pH. This is especially a concern when the product has a pH below the isoelectric point of any such proteins, where it is generally believed that the proteins will precipitate to form a curd. In addition, even if a curd is not formed initially, all of the products containing milk are subject to shelf stability concerns relating to separation. In addition, products are always subject to concerns regarding desirable taste and mouthfeel. Taste is a significant problem, but it is more subjective and open to different evaluations by consumers having a variety of different likes and dislikes. Mouthfeel is critical as well, but generally somewhat less subjective than taste. The present inventions provide stable products that are believed to have especially good stability, desirable taste and desirable mouthfeel. As such, the preferred products advance the technology available to the industry for providing healthful beverage products to consumers seeking high quality milk and fruit beverages to enhance their lives.
Although milk products containing fruit flavors are known, commercial products containing juice generally only have from about 5-10% of milk in them, presumably because it is believed to be problematic to add more and still have a stable product. These products may also include added stabilizers and emulsifiers. Many of these products have a chalky feel in the consumer's mouth, however, and do not provide a significant amount of milk in any case.
There have been a number of processes for preparing milk/juice drinks having an acid pH. These methods usually incorporate soured or fermented milk having a pH believed to be in the neighborhood of about 4. For example, U.S. Pat. No. 3,625,702 to Exler discloses the preparation of sour milk drinks which are naturally or synthetically soured. A mixture of pectin and sugar is stirred into the soured milk and the temperature is adjusted to a temperature above 50 degrees centigrade and the mixture is homogenized and pasteurized. Others have removed components of the milk and juice to produce products they indicate to be stable. For instance, in U.S. Pat. No. 4,676,988, milk and juice are subjected to cation and anion exchange and then homogenized and optionally pasteurized or sterilized and/or carbonated to prepare a juice drink containing some milk. In U.S. Pat. Nos. 3,764,710 and 4,061,792, milk/juice beverages are formed by removing pectic substances and tannins from fruits or fruit extracts. U.S. Pat. No. 5,648,112 to Yang, et al. disclose the use of stabilizers and processing steps to stabilize a beverage containing milk and a food acid, preferably fruit juices. The patent discloses the use of high sheer mixing instead of homogenization to reduce particle size to about 0.8 microns. Stabilizers include a variety of gums including pectin and carboxymethyl cellulose (CMC).
Takahata (U.S. Pat. No. 4,212,893) discloses the use of locust bean gum and pectin to stabilize whole milk before adding fruit juice or other organic acids. Stirring is required before the beverage is homogenized and sterilized. The use of whole milk is disclosed and the disclosure indicates that the locust bean gum coats the milk fat solids to prevent aggregation.
Nishiyama (U.S. Pat. No. 4,078,092) discloses the use of carboxymethyl cellulose (CMC) to form a stable, uncoagulated milk/apple juice drink.
Dulebohn (U.S. Pat. No. 6,171,633) discloses a milk-based drink containing milk, fruit or vegetable juice, gum-based stabilizers and a composition containing an amino acid, an organic acid or inorganic acid, and a metal ion having a pH from 3.0 to 7.0, preferably from 3.0 to 4.6.
Wisler et al. (U.S. Pat. No. 5,202,145) disclose an aqueous shelf-stable beverage product including water; milk solids; an acidic flavoring agent; disodium phosphate; potassium hydroxide and a two component stabilizing system wherein the first component includes monoglycerides and up to 10% by weight diglycerides, and the second component includes carrageenin or pectin. The shelf-stable beverage product is disclosed to have a pH of about 6.3 to about 6.5.
While there has been significant interest in producing non-fermented milk products containing acid pH juices, most have been unsuccessful in achieving incorporation of a large amount of milk in a stable milk and juice product that has desirable flavor and mouthfeel and suitable stability for delivery to the consumer in a common retail market delivery environment typical in the United States and other Western countries.
It is desirable, therefore, to provide a stable milk product which contains a significant percentage of milk and juices from fruit and other natural products. It is further desirable to provide such a milk product that consists of all natural ingredients. It is also desirable to provide a milk product, which does not have a chalky mouthfeel when tasted by a consumer.